Advertisements
Advertisements
प्रश्न
A car travels 30 km at a uniform speed of 60 km/h and the next 30 km at a uniform speed of 20 km/h. What is its average speed?
उत्तर
Car travls 30 km distance with speed 60 km/hr
Time taken by car to travel this distance = 30/60 = 0.5 hr.
Car travels another distance of 30 km with speed of 20 km/hr.
Time taken by car to travel this distance = 30/20 = 1.5 hr.
Total time taken = 1.5 + 0.5 = 2 hr.
Total distance = 30+ 30 = 60 km.
Average speed of car = 60/2 = 30 km/hr.
APPEARS IN
संबंधित प्रश्न
Suppose the two photographs, shown in Figure 1 and Figure 2, had been taken at an interval of 10 seconds. If a distance of 100 metres is shown by 1 cm in these photographs, calculate the speed of the fastest car.
Figure 1 Vehicles moving in the same direction on a road
Figure 2 Position of vehicles shown in Figure 1 after some time
______ is a scalar quantity.
For a body moving along a circular path, show that:
Linear speed = Angular velocity X radius of the circle
On a 120 km track, a train travels the first 40 km at a uniform speed of 30 km/h. How fast must the train travel the next 80 km, so as to average 60 km/h for the entire trip.
Complete the analogy.
Distance : metre :: Speed: ______?
Speed is a ______ quantity whereas velocity is a ______ quantity.
Distances between two cities are measured in kilometres.
Usain Bolt crossed 100 meters in ______ seconds and made a world record.
A spaceship travels 36,000 km in one hour. Express its speed in km/s.
Assertion: The speed of a body can be Negative.
Reason: If the body is moving in the opposite direction of positive motion, then its speed is Negative.
